Conventionally, air-gap devices may be installed in plumbing waste lines as a safety device to prevent drain water from entering a clean water system. Typically, the air-gap device is installed upstream of a drain to prevent back up of drain water into a clean water system or conduit. As the name suggests, and as shown in FIGS. 1A and 1B, conventional air-gap devices 10 include an open space at ambient conditions (the “air-gap” 15) between an outlet 11 of a first fluid conduit 12 and an inlet 13 of a second fluid conduit 14. As a result, if the unpressurized drain, or second fluid, line 14 were to become stopped or clogged (e.g., by small pieces of food), the air-gap device 10 would leak incoming water from the pressurized first fluid conduit 12 via the air-gap 15 into a nearby sink 19 or other water reservoir.
Air-gaps have been incorporated or integrated into various faucets or spouts connected to under-sink appliances, e.g., instant hot water heaters and reverse osmosis (RO) units. In these applications, the air-gap prevents waste fluid from being forced or siphoned back into the storage tank or reservoir of the under sink appliance.
Many U.S. states and cities, such as California, require plumbing of new homes to include an air-gap device 10 between a drain hose 17 of a dishwashing device, such as a dishwasher 18, and its drain line 16. This requires providing, in a kitchen counter top 22, a first opening 24 for receiving a conventional hot and cold water faucet 20 and another opening 26 for receiving the air-gap device 10. Advantageously, installing an air-gap device 10 above the counter top 22 prevents a clogged drain or sink 19 backup directing contaminated water back into the dishwasher 18. This arrangement has several disadvantages.
First, it requires providing in the counter top 22, e.g., by coring, by drilling, and the like, an additional opening 26 at a precise location about the opening 28 for the sink 19. Second, typically, the air-gap device 10 cannot be disposed immediately adjacent to the sink 19, hence, the air-gap device 10 is located a short distance 29 from the sink 19, which means that leaking or weeping drain water from the air-gap device 10 must travel over the counter top 22 for some distance 29 before it enters the sink 19, if it drains into the sink 19 at all. Finally, the air-gap device 10 can be noisy, unsightly, and a nuisance when trying to clean around the sink 19.